Trump says he wants to prevent Iran from developing nuclear weapons, yet he wrecked an international agreement that was doing just that. Now we’re edging closer to a war that the US says it doesn’t want but is doing everything to cause.

Instead of the typical bell-shaped curve, the fossil record shows a fat-tailed distribution, with extreme, outlier events occurring with higher-than-expected probability. Using the same mathematical tools that describe stock market crashes, scientists explain the evolutionary dynamics that give rise to universal patterns in the fossil record.

In the right conditions, airplane contrails can linger in the sky as contrail cirrus — ice clouds that can trap heat inside the atmosphere. Their climate impact has been largely neglected in schemes to offset aviation emissions, even though contrail cirrus have contributed more to warming than all CO2 emitted by aircraft since the start of aviation. A new Atmospheric Chemistry and Physics study found that the climate impact of contrail cirrus will triple by 2050.